The Amplified™ formula of our semi-permanent color contains 30% more pigments than our High Voltage® Classic color! This stronger, longer-lasting formula is available in many of our best-selling shades. The Amplified™ version of our vegan hair color stays shiny longer. Long-lasting doesn't mean added chemicals, and you can rest assured that Amplified™ and High Voltage® formulas are free of PPD and ammonia.